<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>清除内外边距</title>

    <style>
        * {
            margin: 0;
            padding: 0;
        }
    </style>

</head>
<body>
    
    <img src="清除内外边距.png" alt="">

    <br><br>

    123
    <ul>
        <li>99999</li>
    </ul>

</body>
</html>